Loom dobby



Dec. 2, `i941.

E. R. HoLM'Es Loom noBBY Filed April 28, 1941 @M l W 6E] ATTORNEY Patented Dec. 2, 1941 LOOM DOBBY vElbridge R. Holmes, Worcester, Mass., assigner to Crompton & Knowles Loom Works, Worcester, Mass., a corporation of Massachusetts Application April 2s, 194.1, senal No. 390,666

9 Claims.

This invention relates to loom dobbies and it is the general object of the invention to improve the dobby ngers and guide racks therefor- Dobbies are customarily made with a number of lingers which are raised and lowered by the pattern mechanism to indicate hooks connected to the harness frames and positioned by the 1ingers for engagement with oppositely reciprocating knives. It is necessary to space the fingers and make provision for removing them readily from the dobby. It is an important object of my present invention to provide an improved form of linger rack so constructed as to guide the dobby lingers in their normal rising and falling motions but permit ready removal should repair be necessary.

In order that the lingers may be located as closely as possible and be made of uniform thickness I make certain of the dobby lingers longer than others and project them through the guide, the shorter lingers being spacedby the guided longer lingers. It is a further object of my present'invention to insure proper spacing of the lingers by providing each linger of one of the sets, preferably the shorter ones, with lateral offsets on each side thereof which engage adjacent lingers to prevent the lingers from sticking to each other and thereby giving false indication to the dobby hooks.

It is frequently desirable to be able to raise the lingers either for removal or to relieve sticking, and the lingers must ordinarily be heavy enough to overbalance the hooks which they control. It is a further object of my present invention to project the longer ngers through the guide racks sufficiently to afford a convenient hand hold, and to provide the shorter fingers with an upstanding head which not only provides the necessary weight but also makes them accessible from points above the longer lingers. In this way both the long and the short fingers are made of the proper weight and both are easily reached by the weaver for removal.

The dobby usually has its fingers arranged in pairs, one pair for each harness frame and when the lingers are of uneven length, as herein, the nger at one side of the dobby will be short and will not be supported either by the rack or a long linger on one of its sides. It is another object of my present invention to provide the guide rack with a guide wing which will position the short nger which has no long linger to guide its outer side.

With these and other objects in view which will appear as the description proceeds, my invention CTL resides in the combination and arrangement of parts hereinafter described and set forth.

In the accompanying drawing, wherein a convenient embodiment of my invention is set forth,

Fig. 1 is a vertical section through the lower part of a dobby made according to my present invention,

Fig. 2 is an enlarged detail plan view taken in the direction of arrow 2, Fig. 1,

Fig. 3 isa View similar yto a portion of Fig. 1, but showing the manner in whichthe lingers may be removed, and

Fig. 4 is a detail perspective of one lower corner of a dobby made according to my inventionlooking in the direction of arrow 4, Fig. 2.

Referring particularly 'to Fig. 1,l the dobby frame I0 supports a pattern cylinder I I rotatable on a shaft I2 and cooperating with a pattern chain I3 having bars I4 provided with pegs I5. The cylinder I I is given a stepby step movement to present the bars I4 over the shaft I2 in succession, and when the pegs are arranged in two rows 'for double indexing, as in the present instance, the cylinder II will be given an advance motion every second beat of the loom by mechanisrn not shown but well understood.

Extending across the dobby frame is a linger supporting bar 20 over which extends a remov- 'able retainer pin 2 I. 'Ihe pattern surface cooperates with a group or set of fingers of two different lengths. The short lingers 22 may be formed with upwardly curled tails 23 for direct engagement with the lower dobby hooks 24, while the long lingers 25 are provided with substantially horizontal tails 2S to exert an upward force on rods 2l for the upper set of hooks not shown.

VAn evener 28 is supported by the dobby frame and extends under the fingers at a distance from rodv 20 to afford a second support for them. The dobby frame includes a barY 29 which extends under the outer ends of the lingers.

The matter thus far described is of common construction and operates in the usual manner. The cylinder II moves progressively around its axis to present pegs and blank spaces under the dobby lingers, the hooks which control the harnesses being down for engagement with the dobby knives not shown when their corresponding fingers are raised, and being held above the path of thel knives when their lingers are down.

In carrying my present invention into effect I providea rack 3l! formed preferably of sheet metal and having a lower supporting web 3l secured by bolts 32 to bar 29. The rack is provided. With vertical slots 33 which extend upwardly from the web 3l and then horizontally and to the left as viewed in Fig. 1 to an attaching web 35 which is integral with the guide bars or walls 35 located between the slots.

The long fingers are provided with heads 40 which project through the slots 33 far enough to be accessible to the weaver for manual lifting. The left edges 4I of the heads 4l) are located at a less distance from the supporting rod 20 than is the right part of web 35 for a reason to be set forth hereinafter. The long fingers 25 are preferably straight throughout their length and are formed of sheet metal.

The short fingers 22 are provided with heads 45 which are preferably higher than heads 4D to permit grasping by the weaver. The short fingers are aligned with the bars 36 and have their left edges 46 as viewed in Fig. 1 to the right of the bars 36 of the rack. In the present instance each of the short fingers 22 has an outer lateral offset 41 on one side thereof for engaging one of the long fingers adjacent to it and has also a second inner offset 48 on the opposite side to engage the othei` long finger adjacent to it. These offset portions provide narrow guide surfaces which slide along the adjacent long fingers and keep the greater part of the short fingers out of contact with the long ones.

As shown at the bottom of Fig. 2 the last finger, which would be at the right as viewed from the left of Fig. 1, is short and has no outer longer finger to guide it, nor is it guided by a slot 33. In order that this last short finger may be held in proper register with its pattern surface I bend one end of the guide rack to form a wing which extends along the offset 41 of said short finger.

In operation, the long fingers 25 selected by the pattern mechanism for raising will move upwardly in the slots 38 relatively to the offsets 41 and 48 of those short fingers which are to remain down. In Fig. 1 the normal down position of the long fingers is shown in full lines while their raised position is indicated in dotted lines. In like manner, any of the short fingers which are to be elevated will move upwardly with relative sliding of their offsets 41 and 48 with respect to any of the long fingers which are to remain down. The normal amount of raising of the long and short fingers with respect to each other is less than the vertical height of the offset guides 41 and 48 and the latter will therefore always remain in guiding engagement with the long fingers. Both the long and short fingers are therefore held substantially vertically and in register with the pegs I5, wing 50 serving as already described to hold the short finger which is at one end of the shed.

Should it be desired to remove either a long or a short finger the retainer pin 2| will be slid endwise through a part of the dobby frame far enough to permit removal of the faulty finger. If the latter be a long finger the operative will raise the projecting head 40 to the position shown in light dotted lines in Fig. 3, with the head 40 projecting above any adjacent heads 45 which may be up. This affords sufficient hand hold to permit the finger to be raised to the heavy dotted line position with head 40 out of the slot 33. The right end of the finger is then raised clear of rod 20 as shown in dot and dash lines of Fig. 3 to disconnect the finger entirely from the dobby. It may then be entirely removed for repair or renewal, and replacement will be effected by steps the reverse of those already described. Should the short finger require removal the operative will engage one of the upwardly extending heads 45 and remove it in substantially the same manner as that described in connection with the long finger. After the detecting finger has been replaced the rod 2| Will be put back in position and the dobby will be ready to resume operation.

From the foregoing it will be seen that I have provided an improved form of guide rack for the long fingers having a web 35 which holds the guide bars 36 properly spaced but is so located relatively to rod 20 as to permit the fingers to be raised completely from the guide as indicated in Fig. 3. It will also be seen that the offsets 4'1 and 48 provide convenient guides for adjacent fingers, serving to center the short fingers over their pegs I5. The guide ribs 41 and 48 are located between the rack and rod 20 and do not interfere with removal of the fingers. While I have shown these guides on the short fingers I do not wish necessarily so to be limited. It will also be seen that the uniformity in weight of the long and short fingers is accomplished in such a Way as to render both of the heads 40 and 45 accessible to the weaver for removal of the fingers. Furthermore the wing 5U of the rack guides the end short finger.

Having thus described my invention it will be seen that changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the invention and I do not wish to be limited to the details herein disclosed, but what I claim is:

1. In a dobby having a frame provided with a finger supporting rod, a set of dobby fingers certain of which are relatively long and others of which are relatively short, said fingers having downwardly opening bearings receiving and supported by said rod, a guide rack secured to the frame and having spaced vertical slots into which the long fingers extend, vertical guide bars for the long fingers between the slots and aligned with the short fingers, and a web connecting the upper ends of the bars and located at a greater distance from said rod and the ends of the long fingers which project through said slots, whereby said long fingers are movable upwardly out of said slots and off said rod.

2. In a dobby having a finger supporting rod, a group of vertically disposed dobby fingers arranged side by side, certain of said fingers being long and others short, guide means remote from the rod to receive and guide the long iingers, said guide means being located beyond the ends of the short fingers with reference to said rod, and vertically extending spacing ribs on the short lingers between said rod and guide means to engage the long fingers.

3. In a dobby having a finger supporting rod, a group of vertically disposed dobby fingers arranged side by side, certain of said fingers being long and constituting one set of fingers and certain other of the fingers being short and constituting another set of fingers, guide means for the set of long fingers located beyond the other set of short fingers with reference to the rod, and vertically extending spacing ribs on the fingers of one set to engage the fingers of the other set, said ribs located between the guide means and said rod.

4. In a loom dobby having a frame and a finger supporting rod, a plurality of fingers resting on the rod, certain of said fingers being longer than others, a guide rack having slots through which extend the ends of the long fingers remote from the rod, a head formed on that end of each finger adjacent the guide, the head of the long fingers being relatively low and projecting beyond the slots with respect to the rod and the heads of the shorter fingers extending above the heads of the longer fingers.

5. In a loom dobby having a frame provided with a supporting rod, a plurality of dobby fingers one end of each of which rests on the rod, certain of said fingers. being longer than other of said fingers, and a guide rack comprising alternate slots and bars, the ends of the long fingers projecting intothe slots and the ends of the shorter fingers aligning with the bars, said ends of the shorter fingers projecting above the ends of the longer fingers.

6. In a loom dobby having a frame provided with a supporting rod and a rack spaced from and substantially parallel to the rod and provided With vertical guide slots alternated with vertical guide bars, a set of long fingers supported in part by the rod and extending through the slots and accessible from that side of the rack opposite the supporting rod, a set of shorter fingers also supported in part by the rod and alternated with the long fingers and aligned substantially with the vertical bars, the short fingers having portions thereof extending to a higher level than portions of the long fingers adjacent thereto.

7. In a loom dobby having a pattern surface provided with pattern elements, a set of dobby fingers arranged side by side for engagement with said pattern elements, certain of said fingers being long and others being short, a guide rack for the long fingers to position the latter for engagement with the pattern elements corresponding thereto, said rack assisting the long fingers to position the short fingers between the long fingers for engagement with the pattern elements corresponding thereto, the finger on one end of said set of fingers being short and having the outer side thereof remote from the set out of positioning relation with respect to any finger, and means to engage said outer side of said short finger and position the latter for engagement with the pattern elements corresponding thereto.

8. In a loom dobby having a pattern surface provided with pattern elements, a set of dobby fingers arranged side by side for engagement with said pattern elements, certain of said fingers being long and others being short, a guide rack for the long fingers to position the latter for engagement with the pattern elements corresponding thereto, said rack assisting the long fingers to position the short fingers between the long fingers for engagement with the pattern elements corresponding thereto, the finger on one end of said set of fingers being short and having the outer side thereof remote from the set out of positioning relation with respect to any finger, and means positioned by said rack to engage said outer side of said short finger and position the latter for engagement with the pattern elements corresponding thereto.

9. In a loom dobby having a pattern surface provided with pattern elements, a set of dobby fingers arranged side by side for engagement with said pattern elements, certain of said fingers bev ing long and alternated with other fingers which are short, a guide rack for the long fingers to position the latter for engagement with the pattern elements corresponding thereto, said rack assisting the long fingers to position the short fingers between the long fingers for engagement with the pattern elements corresponding thereto, the finger on one end of said set of fingers being short and having the outer side thereof remote from the set out of positioning relation with respect to any finger, and means to engage said outer side of said short finger and position the latter for lengagement with the pattern elements corresponding thereto.

ELBRIDGE R. HOLMES. 

